Joint for reinforced concrete pile sections

ABSTRACT

The invention relates to providing a stiff pile splice ( 2   a,    2   b ) between driven reinforced concrete piles ( 1   a,    1   b ) to join them together end-to-end, with the ends of both reinforced concrete piles ( 1   a,    1   b ) to be joined having an end surface. The connecting means consist of lock rods ( 5   a,    5   b ) provided with crosswise holes ( 6   a,    6   b ), cylindrical lock sockets ( 7   a,    7   b ) provided with a crosswise through-hole ( 23 ) to which tube-like parts ( 8   a,    8   b,    9   a  and  9   b ) and the locking pins ( 10   a ) are attached. A pair of splices consists of two similar splicing pieces. The splicing piece is installed to the end of the concrete pile in connection with casting. In order to reduce the cost of manufacture and materials of the splicing pieces and to achieve reliability in operation, they are made by machining or welding. Preferably, the hole ( 6 ) in the lock rod and the hole ( 19   a ) of the crosswise tunnel ( 9 ) extending through the lock socket have an eccentric disposition relative to each other.

OBJECT OF THE INVENTION

The present invention relates to a stiff pile splice for concrete pilings. The concrete pile comprises

-   -   a square base to which the fastening components consisting of         protruding lock rods and opposing lock sockets featuring         cavities intended for the insertion of the lock rods;     -   connecting means featuring the required crosswise holes and a         locator tube for the insertion of the locking pin;     -   a locking pin penetrating into a tunnel formed by the tubes and         pressing the lock socket and lock rod against each other while         pre-tensioning the pile splice and being locked permanently in         position as a result of the outer edge of the tube being bent         over the locking pin.

In a stiff pile splice, the connecting ends of driven reinforced concrete piles feature box-like or plate-like parts to which the locking means are attached. The locking means consist of protruding pins and sleeves inside the box, both of which have a suitable hole to which an expansion locking pin is driven, and of at least a second flat connecting means placed crosswise relative to the longitudinal direction of the piles extending, at the joint, inside each other in the longitudinal direction of the piles being positioned in opposite positions substantially aligned providing a splicing point where these holes of said connecting means are aligned, and crosswise locking pins extending across the connecting means. The locking means pre-tensions the splice tightly together allowing it to withstand forces acting on it from all directions.

STATE OF THE ART

A number of solutions have been proposed for splicing reinforced concrete piles. A common method of splicing piles is to provide the ends of the piles to be joined together with four longitudinal locator and locking pins with crosswise holes or grooves that are inserted into the corresponding recesses in the opposing pile ends after the piles have been placed on top of each other in order to be spliced. The pile splice is locked in position by driving locking pins or keys from the side through the crosswise holes or grooves positioned at the corresponding positions at the pile ends. This method of joining piles together has, however, proved to be complicated to manufacture and it is difficult to make it fit accurately because of the variations in the dimensions of the base plates. Additionally, a problem with all known pile splices is to how to manage to position the splicing half squarely on top of the pile in connection with casting because they can only be locked to the splice casting chute at two corners provided with protruding male locking means. This type of splices varies very much in detail. However, they exhibit numerous drawbacks. First, the structure of known joints is complicated, expensive to manufacture and unreliable in service. Second, both the lock socket and lock rod must be made of solid steel by machining, which results in considerable wastage of raw material and makes the final product heavy and expensive. Additionally, the lock socket is a closed construction easily penetrated by water which then freezes at sub-zero temperatures, meaning that pile splicing cannot be carried out. The removal of ice is highly complicated in pile-driving conditions. Because the type of pile splices described above have proved to be extremely complicated in practical applications, attempts have also been made to develop a range of connecting means for joining reinforced concrete piles together.

Purpose of the Invention

The purpose of the present invention is to provide a simpler stiff pile splice for use in reinforced concrete piles by eliminating the drawbacks exhibited by known similar splices. More specifically, the invention seeks to provide a stiff pile splice with low cost of materials and labour in production. Another purpose of the invention is to provide a pile splice with a locking system that is not loosened even by a large number of impacts. Still a further objective of the invention is to provide a pile splicing solution to whose locking means reinforcement can be threaded or welded, and to provide a locking joint that can be fixed to the casting chute at all the four corners thanks to parallel crosswise holes extending all the way across the structure.

Characteristics of the Invention

In a concrete pile splice in accordance with the invention,

-   -   the locking means are provided with suitable crosswise locator         tube perforation to permit the locking pin being driven into the         tube-like tunnel of the locking joint to press the lock rod and         lock socket firmly against each other;     -   the lock sockets are interconnected with tube-like parts;     -   the locking pin is round in cross-section;     -   and the locking pin is capable of being driven into the         tube-like tunnel from the side.

The purposes of the invention are achieved with a pile splice in which the locking means are provided with a suitable crosswise hole permitting the locking pin being drive home into a tube-like tunnel to enable the splice withstand forces acting on it from all directions. The locking pin is locked in position by bending the wall of the tube-like part over the conical part of the locking pin.

The pile splice in accordance with the invention offers a number of benefits. Thanks to simple construction, substantial savings are achieved in the cost of materials and labour. As a result, a non-loosening locked splice is accomplished even after a large number of impacts. At the same time, this construction prevents the problems caused by water freezing in the lock socket on the pile-driving site when piles are spliced. Additionally, the invention provides a locked splice that does not have to be anchored in the base plate using load-bearing welds.

In one embodiment of the invention,

-   -   the locking pin is round with no shoulders and conical in shape         at both ends, so that the cross section is identical with that         of the crosswise holes substantially in the lock components;     -   the tube-like parts in the splice form a crosswise tunnel in the         pile serving as casting formwork and as an access route for the         locking pin;     -   the crosswise tubes in the splice are positioned in the lock rod         in such a way that they pre-tension the splice as a result of         the deflection of the locking pin.

The round, shoulderless locking pin may be conical at one end only.

In a second embodiment of the invention

-   -   the first piece to be joined consists of a reinforced concrete         pile with the connecting means at its end consisting of a round         protrusion (qty 1-8) with a round through-hole such that the         other piece to be joined is a rock point with connecting means         compatible with the splicing means in terms of cross section;     -   the connecting means of the reinforced concrete pile and the         rock point are interlocked with a locking pin supported on the         connecting means placed eccentrically at the distance required         for pre-tensioning.

The locking pin can also be locked later by bending the wall of the protective tube over the pin end to prevent it from being dislodged.

EXAMPLES OF APPLICATIONS

The invention is explained in detail in the figures included in the attached drawings. However, the invention is not intended to be limited to the embodiments illustrated by the examples shown in the figures.

List of Figures

FIG. 1 shows an axonometric view of the ends of two reinforced concrete piles with compatible connecting means

FIG. 2 shows the vertical section of two compatible connecting means

FIG. 3 shows a vertical section of the ends of two joined reinforced concrete piles with compatible connecting means

FIG. 4 shows 1 part in a vertical section of the ends of two joined reinforced concrete piles with compatible connecting means

FIG. 5 shows a lateral view of the vertical section of connecting means between two reinforced concrete piles in accordance with the second embodiment

FIG. 6 shows a vertical section of the connecting means in FIG. 5 interconnected.

FIG. 7 shows a section of one part of the connecting means

FIG. 8 shows a vertical section of the reinforced concrete pile splice in accordance with an embodiment of the invention

FIG. 9 shows a section of one part of the connecting means

FIG. 10 shows a lateral view of one embodiment of the connecting means pin

FIG. 11 shows a lateral view of the section of one embodiment of the connecting means

FIG. 12 shows a section of a reinforced concrete pile at the connecting means.

EXPLANATION OF THE FIGURES

FIG. 1 illustrates a situation in which two reinforced concrete piles 1 a and 1 b are to be joined together with the pile ends close to each other but still not touching. Piles 1 a and 1 b are primarily made of concrete 1, in addition to which they contain reinforcement bars that are not shown. Instead, FIG. 1 shows the structure of the connecting means 2 a and 2 b of the reinforced concrete piles 1 a and 1 b in more detail. Both splicing halves 2 a and 2b comprise an end plate 3 a and 3 b, respectively, possibly with edges 12 a-12 b, as well as welded anchoring devices 4 a and 4 b, lock rods 5 a and 5 b, lock sockets 7 a and 7 b, locator tubes 8 a-b and 9 a-b, and locking pins 10 a and 10 b.

In FIG. 1, the splicing half 2 a of the upper reinforced concrete pile 1 a comprises the base plate 3 a featuring suitable holes 11 a for the insertion of lock rods 5 a and lock sockets 7 a and forming, together with the partly bent sides 12 a, the box-like part 3 a. Fixed to the opposite sides (or corners) of the base plate 3 a, there are lock sockets 7 a aligned with the holes 13 a in the base plate 3 a, while fixed to the opposite sides (or corners) there are lock rods 5 a provided with a crosswise hole 6 a in the protruding section. The inner surface of the protruding lock rod 5 a extends though the base plate 3 a to which a reinforcement bar 4 a is welded to provide bonding. The lock rods 7 a are interconnected with tube-like parts 8 a and 9 a. Similarly, a cylindrical lock socket 7 b with a crosswise hole 8 b to which tube-like parts 8 b and 9 b are attached is shown in FIG. 1 welded to the splicing half 2 b of the lower reinforced concrete pile. Facing the concrete, the cylindrical part 7 b has a base to which reinforcement bar 4 b has been welded to provide bonding. Lock rods 5 b have been attached to the opposite sides (or corners) of the base plate 3 b. The reinforcement bars 4 b are fixed to the lock rods 5 b by welding or with threads.

FIG. 1 shows that the locking means 5 a-b and 7 a-b can be placed on the same sides or at opposite corners.

FIG. 2 shows a vertical section of the structure of the reinforced concrete piles 1 a and 1 b at one splice before the piles are joined together. Extending through the base plate 3 a, there is attached to the upper pile 1 a the lock rod 7 a, to which parallel tube-like parts 8 a and 9 a are attached, placed in hole 23 of the lock socket 7 a in such a way that dimension 18 a is suitably greater than dimension 18 b, thereby providing the necessary pre-tensioning of the splice by the action of the deflection of the locking pin 10 a. The figure shows that dimension 15 a in the lock socket 7 a and the dimension 15 b in the lock rod 5 b can be machined highly accurately to the required size in order to ensure adequate tightness of the splice. This provides optimum tightness because dimension 15 a is a few tenths of a millimetre greater than dimension 15 b, forcing the locking pin 10 a to deflect when two piles are joined together. Additionally, FIG. 2 shows that the splicing half 2 a of the upper pile 1 a comprises protective caps 16 and 17 to prevent the ingress of concrete into the locking means during casting. The protective cap 17 features the protrusion 17 a, which makes it possible to bend the wall of the tube 8 a so as to prevent the locking pin 10 a from being dislodged when the pile is driven into the ground.

FIG. 2 shows the relative dimensions of the connecting means indicated by alpha-numeric symbols 15 a and 15 b and determined from the adjoining surfaces of the piles. These dimensions are of critical importance for the proper in-service performance of the connecting means 7 a and 5 b. The tube-like parts 8 a and 9 a form a crosswise tunnel 19 a extending across the pile 1 a. As a result, casting tools can be used to position the splicing half 2 a squarely perpendicular to the longitudinal direction of the pile. Additionally, FIG. 2 shows that the lock rod 5 b contains the groove 14 sized to dimension 15 b from the centre line of the crosswise hole 6 b.

FIG. 3 shows a section of the reinforced concrete piles 1 a and 1 b joined together with the locking pins 10 b in position. The lengths of the locking pins 10 b are selected so as to ensure that both can be driven home while preventing the other pin from being dislodged. Additionally, FIG. 3 shows that any variation in the thickness tolerances of the base plates 3 a and 3 b does not affect the tensioning of the splice. The splice is designed so that the base plate 3 a-b only serves as a locator of the connecting means 7 a 5 b. Additionally, FIG. 3 shows that the lock rod 5 b has a conical head 5 c in order to facilitate splicing.

FIG. 4 shows a vertical section of the structure of reinforced concrete piles 1 a and 1 b at one splice when joined together with the locking pin 10 b secured by bending the wall 20 of the tube 8 a in order to prevent the locking pin 10 b from being dislodged. The wall of the tube 8 a is hammered into position using a suitable tool in order to provide the barrier 20 by making use of the groove 21 when the pile is spliced. FIG. 4 shows that the lock socket 7 a includes the cavity 22 of a size that accepts the lock rod. Additionally, FIG. 4 shows that the lock socket 7 a can also be made of a tube with the required crosswise hole for fixing the tubes 8 a and 9 a.

In the splice between reinforced concrete piles 1 a and 1 b shown in FIG. 5, the lock rod 5 is positioned in the lock socket 7 of the reinforced concrete pile 1 b such that the hole 6 of the lock rod 5 and hole 19 a of the crosswise tunnel 9 extending through the lock socket 7 have an eccentric disposition relative to each other.

FIG. 6 shows that when the locking pin 10 of the splicing device shown in FIG. 5 is driven through the holes 19 a of the crosswise tunnel 9 extending through the lock socket 7 and the hole 6 of the lock rod 5, the eccentricity of the holes causes the locking pin 10 to cold-form and deflect as shown in FIG. 6. At the same time, the locking pin bent in the splice between the reinforced concrete piles 1 a and 1 b pre-tensions the joint, making it extremely strong.

FIG. 7 shows the structure of the lock socket 7 of the reinforced concrete pile 1 b. The lock socket 7 consists of the sleeve 26 and is attached to the hole 11 in the base plate 3. Preferably, use is made of the piece 24 detached from the plate 3 for making the hole 11 by welding it to serve as a base for the lock socket 7. A notch 26 is provided in the side of the sleeve 25, making it possible to position the sleeve 25 in the hole 11 accurately flush with the base plate 3 surface. This ensures that the holes 27 of the sleeve 25 are positioned with great accuracy to achieve the preferred eccentricity of the holes.

FIG. 8 shows a splicing method for reinforcement bars 4 in which the reinforcement bars are welded from the side with welds 28 to the structures of the connecting means. This ensures a strong bond for the reinforcement bars 4.

In FIG. 9, a notch 26 is provided in the base plate 3 joint to prevent the water contained in concrete from leaking into the splicing structures.

In FIG. 10, a textured surface 29 is provided at the end of the locking pin 10 to further enhance the retention of the locking pin 10.

FIG. 11 shows a structure in which a retaining spring 30 is provided at the edge of the hole 19 a of the tunnel 9 extending through the lock socket 7 to further improve the retention of the locking pin 10 in the locked position.

FIG. 12 shows an embodiment in which holes 31 are provided at the edge of the base plate 3 of the reinforced concrete pile for pre-tensioning cables.

Additional Comments

It is obvious to a professional trained in the art that the various embodiments of the invention may vary within the limits defined by the scope of protection provided by the claims.

REFERENCE NUMBERS

-   1 reinforced concrete pile -   2 splicing half -   3 base plate -   4 reinforcement bar (tie bar) -   5 lock rod -   5 c lock rod bevel -   6 lock rod crosswise hole -   7 lock socket -   8 outer locate tube -   9 locator tube between lock sockets -   10 locking pin -   10 c locking pin bevel -   11 base plate holes for lock rod -   12 edge collar -   13 base plate holes for lock socket -   14 lock rod shoulder -   15 centre line of lock rod crosswise hole from shoulder -   16 lock socket protective cap -   17 protective tube cap -   18 a distance between locator tubes in lock socket -   18 b lock rod diameter -   19 lock rod bevel -   19 a tunnel opening for locking pin -   20 protective tube locking bend -   21 groove in concrete to facilitate tube wall bending -   22 lock socket inner cavity -   23 diameter of lock socket crosswise hole -   24 lock socket base -   25 sleeve -   26 notch -   27 hole -   28 weld -   29 surface texture -   30 retaining spring 

1. A joint for a concrete pile section comprising: a first end plate for connecting to the concrete pile; a plurality of spaced apart lock rods extending substantially perpendicular to the first end plate; a plurality of spaced apart lock sockets extending substantially perpendicular to the first end plate, wherein each of the plurality of lock sockets has a cavity-forming sleeve with a shoulder portion cut into at least part of the end of the sleeve and axially-aligned crosswise through-holes on opposite walls of the sleeve, wherein the shoulder portion attaches to the first end plate such that the axis of the crosswise through-holes is eccentrically offset in the socket extending direction relative to a mating lock rod inserted in the cavity; and at least one pin-receiving member interconnected between the crosswise through-holes of at least two of the plurality of lock sockets, wherein the member extends substantially across the first end plate.
 2. The joint according to claim 1, wherein a portion of the pin-receiving member extends a distance into one of the crosswise through-holes.
 3. The joint according to claim 1, wherein the pin-receiving member comprises: a first pin-receiving portion extending from a first peripheral edge of the first end plate into one of the crosswise through-holes; a second pin-receiving portion extending between two crosswise through-holes and substantially axially-aligned with the first pin-receiving portion; and a third pin-receiving portion extending from a second peripheral edge of the first end plate into one of the crosswise through-holes and substantially axially-aligned with the first and second pin-receiving portions.
 4. (canceled)
 5. The joint according to claim 1, further comprising at least one anchoring device attached to at least one of the plurality of lock rods and at least one of the plurality of lock sockets, wherein the at least one anchoring device extends substantially perpendicular to the first end plate.
 6. The joint according to claim 1, wherein the ends of the plurality of lock rods are conical shaped.
 7. The joint according to claim 1, further comprising a locking pin for inserting into the pin-receiving member.
 8. The joint according to claim 7, wherein one end of the locking pin is partially tapered and wherein at least a portion of the surface of the locking pin is textured.
 9. The joint according to claim 1, wherein each of the plurality of lock rods comprises an annular groove at a portion where the lock rods attach to the first end plate.
 10. The joint according to claim 1, wherein the eccentric offset is a distance 15 a from a surface of the first end plate, which is greater than a distance 15 b of the mating lock rod.
 11. The joint according to claim 1, further comprising a protective cap for inserting into the cavity of the plurality of lock sockets.
 12. The joint according to claim 1, further comprising a protective cap for inserting into an end of the pin-receiving member.
 13. The joint according to claim 12, further comprising a protrusion attached to the protective cap for inserting into a recess.
 14. The joint according to claim 1, further comprising a concrete pile, wherein the joint is attached to an end of the concrete pile.
 15. The joint according to claim 1, further comprising at least one through-hole on the first end plate for accepting a pre-tensioning cable.
 16. The joint according to claim 1, further comprising a retaining clip inserted into an end of the pin-receiving member.
 17. A joint for a concrete pile section comprising: a plurality of spaced apart lock rods attached to a first end plate and extending substantially perpendicular to the end plate, wherein at least two of the lock rods each comprise a crosswise through-hole having an axis substantially parallel to the plane of the first end plate and substantially co-axial to each other; a plurality of spaced apart lock sockets extending from the first end plate in a substantially opposite direction from the plurality of lock rods, wherein at least two of the lock sockets each comprise a cavity-forming sleeve with a shoulder portion cut into at least part of the end of the sleeve and crosswise through-holes through the opposite walls of the sleeve, the through-holes having an axis substantially parallel to the plane of the first end plate and substantially co-axial to each other; a first pin-receiving portion extending from a first peripheral edge of the first end plate into one of the crosswise through-holes of one of the cavities; a second pin-receiving portion extending between two crosswise through-holes of the cavities of the at least two lock sockets and substantially axially-aligned with the first pin-receiving portion; and a third pin-receiving portion extending from a second peripheral edge of the first end plate into one of the crosswise through-holes of the cavities and substantially axially-aligned with the first and second pin-receiving portions, wherein the at least two lock rods and the at least two lock sockets are axially-aligned in the socket extending direction with respective mating lock sockets and lock rods on a second end plate, and wherein the shoulder portion attaches to the first end plate such that the axis of the crosswise through-holes is eccentrically offset in the socket extending direction relative to the lock rods on the second end plate inserted in the cavity.
 18. The joint according to claim 17, wherein the eccentrically offset distance is the difference between the distance 15 a and the distance 15 b.
 19. The joint according to claim 18, further comprising a locking pin inserted into the pin-receiving portions for securing the first and second end plates together.
 20. The joint according to claim 19, further comprising a first concrete pile attached to the first end plate and second concrete pile attached to the second end plate.
 21. A method for making a joint for a concrete pile, comprising the steps of: attaching to a first end plate a plurality of spaced apart lock rods extending substantially perpendicular to the end plate; attaching to the first end plate a plurality of spaced apart lock sockets extending substantially perpendicular to the first end plate, wherein each of the plurality of lock sockets has a cavity-forming sleeve with a shoulder portion cut into at least part of the end of the sleeve and axially-aligned crosswise through-holes on opposite walls of the sleeve, wherein the shoulder portion attaches to the first end plate such that the axis of the crosswise through-holes is eccentrically offset in the socket extending direction relative to a mating lock rod inserted in the cavity; attaching at least one pin-receiving member to the first end plate, wherein the pin-receiving member interconnects the crosswise through-holes of at least two of the plurality of lock sockets, and wherein the member extends substantially across the first end plate.
 22. The method according to claim 21, wherein the lock sockets are made of a longitudinal blank into which the cavities and through-holes are formed.
 23. The method according to claim 21, wherein the pin-receiving member is sized to accept at least one locking pin having a substantially similar cross-section.
 24. The method according to claim 21, further comprising attaching the joint to a concrete pile.
 25. The method according to claim 24, further comprising splicing the pile joint with another pile joint by removably inserting a locking pin into the pin-receiving member.
 26. The method according to claim 25, further comprising crimping an end of the pin-receiving member to secure the locking pin.
 27. The method according to claim 21, further comprising forming a beveled edge on a opening of a crosswise through-hole on the plurality of lock rods.
 28. The method according to claim 21, further comprising the steps of attaching the joint to a joint guide using two casting guide pins.
 29. A method for making a joint for a concrete pile, comprising the steps of: attaching to a first end plate a plurality of spaced apart lock rods extending substantially perpendicular to the end plate; forming in each of at least two of the lock rods a crosswise through-hole having an axis substantially parallel to the plane of the first end plate and substantially co-axial to each other; attaching to the first end plate a plurality of spaced apart lock sockets extending from the first end plate in a substantially opposite direction from the plurality of lock rods, wherein each of the plurality of spaced apart lock sockets is formed from a sleeve having a shoulder portion cut into at least part of the end of the sleeve; forming in each of at least two of the lock sockets a cavity for receiving a mating lock rod on a second end plate; forming two crosswise through-holes through the opposite walls of the sleeves, wherein the through-holes have an axis substantially parallel to the plane of the first end plate; attaching a pin-receiving member extending from a first peripheral edge of the first end plate into one of the crosswise through-holes of one of the cavities, and extending between two crosswise through-holes of the cavities of the at least two lock sockets, and extending from a second peripheral edge of the first end plate into one of the crosswise through-holes of the cavities; and attaching at least one anchoring device to at least one of the plurality of lock rods, or to at least one of the plurality of lock sockets.
 30. The method according to claim 29, wherein the at least two lock sockets are made of a longitudinal blank into which the cavities and through-holes are formed.
 31. The method according to claim 29, wherein the pin-receiving member is sized to accept at least one locking pin having a substantially similar cross-section.
 32. The method according to claim 29, further comprising attaching the joint to a concrete pile.
 33. The method according to claim 32, further comprising splicing the pile joint with another pile joint.
 34. The method according to claim 29, further comprising the steps of: positioning in one of the at least two lock sockets a lock rod on a second end plate such that the axis of the through-hole on the lock socket and the axis of the crosswise through-hole on the lock rod are eccentrically offset relative to each other. 